Safety valve



Dec.-30, 1952 A. n. SANDS 2,623,725

SAFETY VALVE Filed 001;. 30, 1946 3 Sheets-Sheet l INVENTOR Dec. 30,1952 A. D. SANDS 2,623,725

SAFETY VALVE Filed 001;. 30, 1946 5 Sheets-Sheet 2 A. D. SANDS Dec. 30,1952 SAFETY VALVE 3 Sheets-Sheet 5 Filed Oct. 30 1946 INVENTOR PatentedDec. 30, 1952 UNITED STATES PATENT OFFICE SAFETY VALVE Asa D. Sands,Camden, N. J.

Application October 30, 1946, Serial No. 706,650

1 Claim. 1

My invention relates to a safety system for gas and air pressureconduits incident to operation of automatic tools, distribution of gasfor welding, distribution of gas for heating and chemical uses and thelike.

The present application is a continuation in part of my copendingapplication for Safety Valves, Serial No. 551,710 filed August 29, 1944,now abandoned.

The main purpose of my invention is to avoid death or injury to workerswho are likely to be placed in danger in case of the unexpectedbursting, cutting or other leakage of a gas or air conduit, especiallyto those in precarious positions as on scaffolds, decking or incompartments, when using air tools in ship building or the like, orthose engaged in welding; or maintenance or operation of combustion orchemical lines.

A further purpose is to avoid whipping of broken flexible linescontaining gas or air.

A further purpose is to employ a safety valve which will automaticallyrestore operation without location of the valve when the leak isrepaired.

A further purpose is to provide diflerent resultant pressures uponseating a safety valve in opposite directions so that in case of changein pressure, flow or other conditions the valve can meet the differentconditions simply by reversal without disassembly.

A further purpose is to provide means for cutting off a by-pass of asafety valve in case the character of gas makes it unsafe to use thebypass.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate a few only of theembodiments in which my invention may appear, choosing the forms shownfrom the standpoint of convenience in illustration, satisfactoryoperation and clear demonstration of the principles involved.

Figure 1 is a perspective view of an air compressor and air line systemwith an automatic tool at work, embodying my safety valve, butillustrating an assumed condition in case the safety valve did not workor was not employed.

Figure 1 illustrates a variation of Figure 1 applied to a permanentpiping installation.

Figure 2 is a longitudinal sectional view of my improved safety valve.

Figure 3 is a transverse sectional view taken on the line 3-3 of Figure2.

Figure 4 is a detailed perspective view of the valve element shown inFigures 2 and 3.

Figure 5 is a view similar to Figure 2 but showing the valve element inposition corresponding to closure.

Figure 6 is a view similar to Figures 2 and 5 showing a modification.

Figure '7 is a longitudinal central sectional view of a modified valvesimilar to Figures 2, 5 and 6.

Figure 8 is a view similar to Figure '7 showing the valve in a differentposition.

Figure 9 is a fragmentary perspective view of my invention applied to awelding system.

Describing in illustration but not in limitation and referring to thedrawings:

In the prior art there have frequently been industrial accidents due tothe unexpected breaking, cutting or leaking of air or gas hoses, pipesor the like. This condition is hazardous in a number of ways. When theparticular line of conduit is carrying compressed air for drills orother tools as in shipbuilding, the broken end of a flexible hose orother conduit suddenly whips as indicated in Figure 1 at 20 where it isassumed that a hose 2| from an air compressor 22 to an air drill 23 maysuddenly break at the location 20. This whipping end may strike againsta man with great force knocking him off a scaffolding or into the pathof machinery, cranes or the like, or may startle him so that he loseshis balance and falls or is otherwise hurt. In the case of a simplesystem involving a single hose as shown in Fi ure 1, the problem oflocation of the source of difficulty and correction is rather simple,but in the case of a more complex system as shown in Figure l wherethere is a tank or other source of compressed air or the like 24distributing through a main valve 25 to a header 26 connecting tonumerous laterals 21, 21, 21 each of which has one or more air tools, itwill be understood that particularly in shipbuilding where hoses becomecrossed and tangled and are taken into narrow and remote compartments, avery considerable economic loss is involved in the case of unexpectedleakage, because, it is necessary to shut off the main valve 25 untilthe particular lateral causing trouble can be traced down and either out01f or the leak repaired. This is made all the more necessary becausethe blast of air coming out from the broken end at high pressure in asmall compartment is both unpleasant and dangerous, and the workersusually, immediate 1y signal for shut-oils of the system until thedifficulty can be localized.

The hazards suggested above in connection with air tools and the likeare greatly accentuated when explosive, combustible or other dangerousgases are being employed, for example in welding, fuel combustion andchemical processes.

To suggest this condition, I show in Figure 9 a welding equipmentconsisting of a suitable oxygen tank 28 having suitable valves and gages29 and a fuel tank 363 having suitable valves and gages 3i,communicating through respective hoses 32. and 33 to a torch or the-like3d.

Breakage for example at 35, particularly in the fuel line, will not onlycause the line to whip and possibly cause damage or injury, but mayfloodv a compartment or other space with explosive or combustible gasbefore the main control valve: appropriate to the broken line can be outoff.

In order to correct the above-difficultyIIinter-- pose between thesource and the point. of distribution a safety valve 36 which normallyremains open, but. which closes in case of abnormal flow incident tounexpected leakage, and preferably opens automatically again when thedifficulty has been. overcome. My valve is shown in Figure I adjacentthe compressor, in Figure 1 applied to each of the individual lateralsand in Figure'9 applied to the oxygen and fuel lines as they leave thevalves and gages at the tanks.

The valve as. shownin Figures 2 to has a suitably circularbodyslprovidedat the opposite ends with threaded connections forsuitable fittings, andsuitably formed with opposite end section's39 and ii} joined by a unionAn interior v'alv'e' space 32 is provided by. the cooperating sections,and on each section (or permissibly on the only one section as shown inFigure 6-) Ipr'ovi'de a central valve seat 53 or -33, oppositely facing;and in line.

Spiders M and 45 extend across the-valve casing at opposite ends of the.valve space 32 and toward the ends. of, the casing with respect to thevalve seats, and the spiders are provided with centrally cooperating,guidin openings 6 and spring abutments. ll.

Thestem 58 extends longitudinally through the i suitably havingoppositely facing valveportions v 511 (except inFigure 6 where only oneisnecessary) to cooperate with the respective valve seats. Betweenthevalve element and. the spring abutment at each end, I provide valvesprings. 5i and 52;, chosen to exert. a force on compression'sunicienttokeep the valve in open position during normal flow under the particularpressure and volume of flow, but insufficient to prevent closure under.abnormal flow incident to unexpected leakage The springs 5 i anddii arepreferably chosen with slightly different pressures, so that if. it isdecided to-operate theline at different pressure it will not benecessary to disassemble the valves a'n'drep'lace springs, but thevalves can simply be reversed end for end to bring, into play thevspring of. the appropriate stiifness.

By this procedure it is possible to cover a Wide range of operatingconditions from a single valve Without tedious disassembly andreplacement of parts.

When the valve. closes it is desirable to permit it to openautomatically so thatafter location and repair of the leakage it willnot be necessary to search out and open the valve; With this purpose inview, a by-pass. port 53 is extended from end to end through the valveelement, permitting slight leakage when the valve is closed toward thedirection of flow.

In the form as shown in Figures 7 and 8 the spiders are dispensed with,and the valve element is mounted or held floating entirely by thesprings 54 and 55 Which are suitably of conical form engaging inrecesses 56 and 5! of the casing on opposite sides of the valve space42, and beyond the valve; seats ii-3, d3. l hus it is seen that the ends58 of the springs which engage thevalve element 59 not only urge itlongitudinally but locate centrally and prevent the necessity to rigidlyguide the valve element.

In this form the casing has been slightly modilied: to provide anexternal thread at 353' at one end, and the union has been dispensedwith, the sections of the-valve casing being joined by 00- operatingthreads at 59.

In the form of Figures 7 and 3, no by-pass opening 53 is provided in thevalve element but a separateby-pass openingdil extends through the valvecasing" and; is controlled by an additional needle valve Si.This'permits closing off of the by-pass to in case an explosive or.other dangerousgas is used which. would be dangerous to allow to leakthrough the by-pass after the valve is. closed. Thus with the form ofFigures '7 and 8' it is possible to apply the valve without alterationin its structure either to air, to nonexplosivegases', and to explosivegases.

In operation the valve remains in the position shown in Figures 2 and.'7 as long as the system is functioning properly; In case ofleakage, ifthe gas is entering at the right and flowing out the left of Figures 5,.6 and-8,. the valve will seat: to the left, cutting off, instantly theflow at the leak except for minor flow through the by-pass (if this. ispermitted in the form of Figures '2 and 3),. There will then, be novwhippfmgv of the broken-end of' a hose and no danger to the workereither frormthebroken hose or from the air or gas. Where theby-pass isused, as. soon as the leak is repaired, gas flowing through the icy-passwill build. up the pressure in the remote. portion of the. conduitunder. the closed valve and. thus when the pressure. becomes highenough. to. balance thepressur-e onthe cppositeside cf the valvethespring ill will be enabled to. open the valve and the system willautomatically be restored to service.

If in any case the spring is not adequate to maintain the: valve open innormal operation or is too strong to permit closing in the case-of. aleak, the valvecan: be reversed and. the spring of different strength atthe other end. used.

In. View of my invention and disclosure-variationsandmodifications tomeet individual whim or particular need. will doubtless becomeevident toothers skilled in the art, to obtain all or part of the benefits ofmyinvention without copying the structure shown, and I, therefore, claimall such insofar as they fall within the reasonable spirit and scope ofmy claims.

Having thus described my invention what I claim asv new and desire tosecure byLetters Patentis-z in a safety valve, a circular body, valveseats at opposite ends of the body, guide means on the body centrallylocated thereof toward the ends of the body with respect to the valveseats, a stem extending through the guide means, a double valveelementmounted on the stem and adapted alternately to. close one orother of the valve seats, aby pass port through the valve 5 element andsprings of different predetermined strengths surrounding the stem onopposite ends of the valve element urging the valve element away fromthe adjoining guide means with different strengths so to permitadjustment of the valve to different conduit flow and pressureconditions by reversal without disassembly.

ASA D. SANDS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 546,589 Doerhoefer Sept. 17, 1895583,037 Dunham May 25, 1897 693,133 Hennebohle Feb. 11, 1902 NumberNumber

